function circleArea(radius){
    return Math.PI*radius*radius;
}
function circlePerimeter(radius){
    return 2*Math.PI*radius;
}
const radius =3.14;
const area=circleArea(radius);
const perimeter=circlePerimeter(radius);

console.log(`圆的面积是: ${area}`);
console.log(`圆的周长是: ${perimeter}`);
  